To define an attractor is not simple. Tsonis gives the definition of attractors as "a limit set that collects trajectories".(1) A strange attractor is simply the pattern of the pathway, in visual form, produced by graphing the behavior of a system. Since many, if not most, nonlinear systems are unpredictable and yet patterned, it is called strange and since it tends to produce a fractal geometric shape, it is said to be attracted to that shape. A system confines a particular entity and its related objects or processes to an imaginary or real frame as the subject of study, this is its "state space" or phase space. The behavior in this state space tends to contract in certain areas, this contraction is called "the attractor". The attractor is actually "a set of points such that all trajectories nearby converge to it". Now tell me what an attractor is. You can't and neither can I, even with Tsonis's definition. Scientists, mathematicians, and computer specialists can show you pictures of how they operate, but they cannot tell you what they are. Maybe, that is why Daniel Stein, compares Chaos/Complexity to a "theological concept", because lots of people talk about it but no one knows what it really is.(2) (Found in the Preface to the first volume of lectures given at the 1988 Complex Systems Summer School for the Santa Fe Institute in New Mexico)